Put oven rack in middle position and preheat oven to 450°F. Toss cauliflower with 1/4 cup oil, 1/2 teaspoon salt, and 1/8 teaspoon pepper in a large bowl. Spread in 1 layer in a shallow baking pan (1 inch deep) and roast, turning over with tongs halfway through roasting, until tender and golden b...